Carbon nanomaterials may be applied to a variety of fields such as electronic devices, sensors, high-performance composites, and the like due to excellent mechanical properties, electrical selectivity and field emission characteristics thereof.
In particular, since carbon nanomaterials of nanocomposites have nano-size particles, mechanical performance and electrical performance such as strength, wear resistance, or the like may be considerably improved using a small amount of the carbon nanomaterials without any property loss, when the carbon nanomaterials are well dispersed in a polymer matrix.
However, in spite of predicted superior properties of the carbon nanomaterials, mechanical performance or electrical performance of presently prepared carbon nanomaterial composites falls very short of expectations. Such a phenomenon is caused by two elements, namely, dispersion of carbon nanomaterials and compatibility, adhesion, or wetting of nanotubes and polymers.
Carbon nanomaterials have strong electrostatic attraction and thus it is difficult to uniformly disperse the nanomaterials in a polymer matrix. Recently, as a method to effectively disperse the carbon nanomaterials, a method of treating the nanomaterials with ultrasonic waves and the like have been developed and broadly used. However, the carbon nanomaterials are damaged according to intensity of ultrasonic waves and time and thus it is difficult to maintain superior properties and characteristics thereof, and, accordingly, it is difficult to apply the nanomaterials to large-scale production.
In addition, compatibility of the carbon nanomaterials with broadly used thermoplastic polymers is dramatically low, when compared with surface-treated glass fiber or carbon fiber, which are presently used. This is since a portion of a nanotube surface may not interact with thermoplastic polymers. To resolve such a problem, a surface-treatment method through acid treatment and a method of coating noncovalent bonding materials using π-π interaction have been suggested. However, it is difficult to commercialize the methods due to a complex process procedure and high material costs.